InfoScale™ 9.0 Cluster Server Agent for Hitachi TrueCopy/HP-XP Continuous Access Configuration Guide - Windows
- Introducing the agent for Hitachi TrueCopy/Hewlett-Packard XP Continuous Access
- Configuring the agent for Hitachi TrueCopy/Hewlett-Packard XP Continuous Access
- Configuration concepts for the Hitachi TrueCopy/Hewlett-Packard XP Continuous Access agent
- Attribute definitions for the TrueCopy/HP-XP-CA agent
- Before you configure the agent for Hitachi TrueCopy/Hewlett-Packard XP Continuous Access
- Configuring the agent for Hitachi TrueCopy/Hewlett-Packard XP Continuous Access
- Configuration concepts for the Hitachi TrueCopy/Hewlett-Packard XP Continuous Access agent
- Testing VCS disaster recovery support with Hitachi TrueCopy/Hewlett-Packard XP Continuous Access
- How VCS recovers from various disasters in an HA/DR setup with Hitachi TrueCopy/Hewlett-Packard XP Continuous Access
- Setting up fire drill
About preventing split-brain
Split-brain occurs when all heartbeat links between the primary and secondary hosts are cut. In this situation, each side mistakenly assumes that the other side is down. You can minimize the effects of split-brain by ensuring that the cluster heartbeat links pass through a similar physical infrastructure as the replication links. When you ensure that both pass through the same infrastructure, if one breaks, so does the other.
Sometimes you cannot place the heartbeats alongside the replication links. In this situation, a possibility exists that the cluster heartbeats are disabled, but the replication link is not. A failover transitions the original P-VOL to S-VOL and S-VOL to P-VOL. In this case, the application faults because its underlying volumes become write-disabled, causing the service group to fault. VCS tries to fail it over to another host, causing the same consequence in the reverse direction. This phenomenon continues until the group comes online on the final node. You can avoid this situation by setting up your infrastructure such that loss of heartbeat links also means the loss of replication links.